There is little opportunity for a flash chip to be written to in a conventional design of a flat panel display circuit. Generally, data is written to the flash chip before the display product leaves the factory, and when the flash chip is in use, the data is simply read out, with no write operation needed.
Nowadays AMOLED modules are provided with electrical compensation functionality, which requires not only write operations to the flash chip before the product leaves the factory, but also read and write operations to the flash chip when the product is in use. However, an abnormal event, such as a sudden powering down due to e.g. a power outage or an unintentional disconnection of the power plug, may occur when the display product is in use. In this case, if the flash is in a write state, the abnormal event will cause a failure of the write operation, leading to data loss in a corresponding block of the flash. As a write operation cannot be performed to the flash before the corresponding block is erased, it is possible that when an abnormal event (e.g., a power outage) occurs, the compensation data previously stored has been erased while new compensation data has not been written yet. As a result, after re-energization of the display, the displayed content will be abnormal in some regions of the display.
Therefore, there is a need for an improved read and write control circuit and method of the flash chip.